JP2007322842A - Electrophotographic toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic toner excellent in all of low temperature fixability, offset resistance, durability and preservability, and reducing the generation of an offensive odor as well, and to provide a method for producing the same. <P>SOLUTION: The electrophotographic toner comprises: a polyester resin (A); and a polyester resin (B) having a softening point higher than that of the polyester resin (A) by ≥10°C as binding resins. At least either the polyester resin (A) or (B) is a resin derived from (meth)acrylic acid modified rosin having a polyester unit obtained by polycondensating an alcohol component and a carboxylic acid component comprising (meth)acrylic acid modified rosin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrophotographic toner used for developing a latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like, and a method for producing the same.

Along with the development of electrophotographic technology, there is a demand for a toner having excellent low-temperature fixability, offset resistance and storage stability (blocking resistance), and for that purpose, it contains a linear polyester resin that defines physical properties such as molecular weight. Toner (see Patent Document 1), toner containing non-linear cross-linked polyester resin using rosins as an acid component in polyester (see Patent Document 2), rosin modified with maleic acid is used, and fixing property is improved. An improved toner (see Patent Document 3), a toner using a resin obtained by blending a low molecular weight resin and a high molecular weight resin (see Patent Document 4), and the like have been reported.
JP 2004-245854 A JP-A-4-70765 JP-A-4-307557 Japanese Patent Laid-Open No. 2-82267

  However, due to the further increase in speed and energy saving of recent machines, it has been found that conventional binder resins for toner are insufficient for market demand. That is, it is very difficult to maintain sufficient fixability due to shortening of the fixing time in the fixing process and lowering of the heating temperature in the fixing machine. In particular, the method using a low molecular weight resin inevitably involves a decrease in the glass transition point, which causes problems such as toner aggregation during storage.

  In addition, deterioration of the toner due to strong stress during printing and filming due to poor dispersion of the internal additive cause a problem of image deterioration particularly in high-speed continuous printing.

  Furthermore, although the rosin monomer used in Patent Document 2 and Patent Document 3 is effective in improving the low-temperature fixability, it also has a drawback that odor is likely to be generated.

  An object of the present invention is to provide an electrophotographic toner that is excellent in all of low-temperature fixability, offset resistance, durability, and storage stability, and has reduced odor generation, and a method for producing the same. Another object of the present invention is to provide an electrophotographic toner excellent in filming resistance and a method for producing the same.

The present invention
[1] A toner comprising a polyester resin (A) and a polyester resin (B) having a softening point higher than that of the polyester resin (A) by 10 ° C. or more as a binder resin, the polyester resin At least one of (A) and (B) is derived from a (meth) acrylic acid-modified rosin having a polyester unit obtained by condensation polymerization of an alcohol component and a carboxylic acid component containing a (meth) acrylic acid-modified rosin And (2) at least a step of melt-kneading the polyester resin (A) and the polyester resin (B) having a softening point higher by 10 ° C. or more than the polyester resin (A). A method for producing a toner, wherein at least one of the polyester resins (A) and (B) contains an alcohol component and a (meth) acrylic acid-modified rosin. And Bon acid component having a polyester unit obtained by condensation polymerization (meth) method for producing an electrophotographic toner which is acrylic acid-modified rosin.

  The electrophotographic toner of the present invention is excellent in all of low-temperature fixability, offset resistance, durability and storability, and has an excellent effect that odor generation is reduced. In the electrophotographic toner of the present invention, when the resin having a lower softening point is a resin derived from (meth) acrylic acid-modified rosin, a further effect in filming resistance is obtained.

  The toner for electrophotography of the present invention contains, as a binder resin, a polyester resin (A) and a polyester resin (B) having a softening point higher than that of the polyester resin (A) by 10 ° C. or more. At least one of the resin based resins (A) and (B) has, as a raw material monomer, a polyester unit obtained by condensation polymerization of an alcohol component and a carboxylic acid component containing (meth) acrylic acid-modified rosin (meta ) It has one feature in that it is a resin derived from acrylic acid-modified rosin. A resin derived from (meth) acrylic acid-modified rosin can be fixed at an extremely low temperature and has good storage stability. Further, the generation of fine powder in the developing tank is reduced, and the durability is improved. This is because (meth) acrylic acid-modified rosin is a rosin having two functional groups, so that the molecular chain can be extended as part of the main chain of the polyester unit, and the toughness of the resin is increased. It is done. In the present specification, for the sake of convenience, the resin in the present invention is indicated as a resin derived from (meth) acrylic acid-modified rosin, but this “derived” refers to (meth) acrylic acid as at least one raw material monomer. This means that a modified rosin is used.

  On the other hand, the combination of two types of resins with different softening points has been attempted in the past to achieve both low-temperature fixability and durability, offset resistance and storage stability of the toner, but resins with different softening points have different melt viscosities. Therefore, both resins are hardly mixed uniformly, and the dispersibility of internal additives such as a colorant and a release agent is likely to be lowered. However, in the present invention, when the polyester resin having a lower softening point is a resin derived from (meth) acrylic acid-modified rosin, as described above, (meth) acrylic acid-modified rosin is the main chain of the polyester unit. Since the molecular weight of the resin can be increased as a part, it is considered that the melt viscosity is easily increased as compared with the softening point, and the filming resistance accompanying the poor dispersion of the internal additive is considered to be remarkably improved.

  Hereinafter, the resin derived from (meth) acrylic acid-modified rosin will be described. The resin derived from (meth) acrylic acid-modified rosin is used as at least one of two types of polyester resins, that is, polyester resins (A) and (B). In view of the above, it is preferable that at least the polyester resin (A) having a lower softening point is a resin derived from (meth) acrylic acid-modified rosin, and from the viewpoint of durability, both resins, that is, polyester resins ( It is more preferable that both A) and the polyester resin (B) having a softening point higher by 10 ° C. or more than the polyester resin (A) are resins derived from (meth) acrylic acid-modified rosin.

  The (meth) acrylic acid-modified rosin in the present invention is a rosin modified with (meth) acrylic acid, and is abietic acid, neoabietic acid, parastrinic acid, pimaric acid, isopimaric acid, sandaracopimaric acid, dehydroabietic acid , Which is obtained by addition reaction of (meth) acrylic acid to rosin mainly composed of lepopimaric acid, etc., specifically, lepopimaric acid having a conjugated double bond in the main component of rosin, abietin It can be obtained through Diels-Alder reaction under heating with acid, neoabietic acid and parastrinic acid, and (meth) acrylic acid.

  In the present specification, “(meth) acryl” means acryl or methacryl. Therefore, (meth) acrylic acid means acrylic acid or methacrylic acid, and “(meth) acrylic acid-modified rosin” means rosin modified with acrylic acid or rosin modified with methacrylic acid. The (meth) acrylic acid-modified rosin in the present invention is preferably an acrylic acid-modified rosin modified with acrylic acid having little steric hindrance from the viewpoint of reaction activity in the Diels-Alder reaction.

  The degree of modification of rosin with (meth) acrylic acid ((meth) acrylic acid modification degree) is preferably 5 to 105, more preferably 20 to 105, from the viewpoint of increasing the molecular weight of the polyester unit and reducing the low molecular weight oligomer component. Preferably, 40 to 105 is more preferable, and 60 to 105 is more preferable.

  The degree of (meth) acrylic acid modification is expressed by the formula (A):

(Wherein X ₁ is the SP value of (meth) acrylic acid-modified rosin for calculating the degree of modification, and X ₂ is (meth) acrylic acid-modified obtained by reacting 1 mol of (meth) acrylic acid with 1 mol of rosin. Saturated SP value of rosin, Y indicates SP value of rosin)
Is calculated by Here, the SP value means a softening point measured by a ring and ball automatic softening point tester described later. The saturated SP value means the SP value when the reaction between (meth) acrylic acid and rosin is reacted until the SP value of the obtained (meth) acrylic acid-modified rosin reaches a saturation value. The molecule of the formula (A) means the degree of increase in the SP value of rosin modified with (meth) acrylic acid, and the larger the value of the formula (A), the higher the degree of modification.

  The production method of the (meth) acrylic acid-modified rosin is not particularly limited. For example, the rosin and (meth) acrylic acid are mixed and heated to about 180 to 260 ° C., preferably 180 to 210 ° C. By the reaction, (meth) acrylic acid can be added to an acid having a conjugated double bond contained in rosin to obtain a (meth) acrylic acid-modified rosin. The (meth) acrylic acid-modified rosin may be used as it is, or may be used after purification through an operation such as distillation.

  The rosin used in the (meth) acrylic acid-modified rosin in the present invention is natural rosin obtained from pine, isomerized rosin, dimerized rosin, polymerized rosin, disproportionated rosin, and the like, abietic acid, neoabietic acid, A process for producing natural rosin pulp from the viewpoint of color, although any known rosin can be used as long as it is a rosin mainly composed of parastrinic acid, pimaric acid, isopimaric acid, sandaracopimaric acid, dehydroabietic acid, lepopimaric acid, etc. Natural rosin such as tall rosin obtained from tall oil obtained as a by-product, gum rosin obtained from raw pine sprout, wood rosin obtained from pine stumps is preferred, and tall rosin is more preferred from the viewpoint of low-temperature fixability.

  The (meth) acrylic acid-modified rosin in the present invention is obtained through a Diels-Alder reaction under heating, so that impurities that cause odor are reduced and the odor is low, but the odor is further reduced. From the viewpoint of improving the storage stability, the (meth) acrylic acid-modified rosin is preferably obtained by modifying a rosin (purified rosin) whose impurities have been reduced by a purification process with (meth) acrylic acid. ) What is obtained by modification with acrylic acid is more preferred.

  The purified rosin in the present invention is a rosin in which impurities are reduced by the purification step, and the impurities contained in the rosin are removed by purifying the rosin. The main impurities are 2-methylpropane, acetaldehyde, 3-methyl-2-butanone, 2-methylpropanoic acid, butanoic acid, pentanoic acid, n-hexanal, octane, hexanoic acid, benzaldehyde, 2-pentylfuran, 2 , 6-dimethylcyclohexanone, 1-methyl-2- (1-methylethyl) benzene, 3,5-dimethyl-2-cyclohexene, 4- (1-methylethyl) benzaldehyde and the like. In the present invention, among these, the peak intensity of three types of impurities, hexanoic acid, pentanoic acid, and benzaldehyde, detected as a volatile component by the headspace GC-MS method, can be used as an indicator of purified rosin. In addition, the use of the purified rosin in the present invention makes the improvement of odor one of the problems compared to the conventional polyester using rosin, because the specific volatile component rather than the absolute amount of impurities is used as an index. by.

That is, the purified rosin in the present invention has a peak intensity of hexanoic acid of 0.8 × 10 ⁷ or less and a peak intensity of pentanoic acid of 0.4 × 10 ⁷ or less under the measurement conditions of the headspace GC-MS method described later. Rosin having a peak intensity of benzaldehyde of 0.4 × 10 ⁷ or less. Furthermore, from the viewpoint of storage stability and odor, the peak intensity of hexanoic acid is preferably 0.6 × 10 ⁷ or less, and more preferably 0.5 × 10 ⁷ or less. The peak intensity of pentanoic acid is preferably 0.3 × 10 ⁷ or less, and more preferably 0.2 × 10 ⁷ or less. The peak intensity of benzaldehyde is preferably 0.3 × 10 ⁷ or less, and more preferably 0.2 × 10 ⁷ or less.

Furthermore, from the viewpoint of storage stability and odor, it is preferable that n-hexanal and 2-pentylfuran are reduced in addition to the above three substances. The peak intensity of n-hexanal is preferably 1.7 × 10 ⁷ or less, more preferably 1.6 × 10 ⁷ or less, and further preferably 1.5 × 10 ⁷ or less. The peak intensity of 2-pentylfuran is preferably 1.0 × 10 ⁷ or less, more preferably 0.9 × 10 ⁷ or less, and further preferably 0.8 × 10 ⁷ or less.

  As a purification method of rosin, known methods can be used, and methods such as distillation, recrystallization, extraction and the like can be mentioned, and purification by distillation is preferable. As the distillation method, for example, the method described in JP-A-7-286139 can be used, and examples thereof include vacuum distillation, molecular distillation, steam distillation, etc., but purification by vacuum distillation is preferable. For example, distillation is usually performed at a still temperature of 200 to 300 ° C. at a pressure of 6.67 kPa or less, and methods such as ordinary simple distillation, thin film distillation, rectification, etc. are applied. On the other hand, 2 to 10% by weight of a high molecular weight substance is removed as a pitch component and at the same time, 2 to 10% by weight of an initial fraction is removed.

  The softening point of the rosin before modification is preferably 50 to 100 ° C, more preferably 60 to 90 ° C, and further preferably 65 to 85 ° C. The softening point of rosin in the present invention means a softening point measured after the rosin is once melted and naturally cooled in an environment of a temperature of 25 ° C. and a relative humidity of 50% for 1 hour by the method described later.

  Furthermore, the acid value of rosin before modification is preferably 100 to 200 mgKOH / g, more preferably 130 to 180 mgKOH / g, and further preferably 150 to 170 mgKOH / g.

  The content of the (meth) acrylic acid-modified rosin is preferably 5% by weight or more and more preferably 10% by weight or more from the viewpoint of low-temperature fixability in the carboxylic acid component of the resin derived from the (meth) acrylic acid-modified rosin. Further, from the viewpoint of storage stability, it is preferably 85% by weight or less, more preferably 65% by weight or less, and further preferably 50% by weight or less. From these viewpoints, the content of the (meth) acrylic acid-modified rosin is preferably 5 to 85% by weight, more preferably 5 to 65% by weight in the carboxylic acid component of the resin derived from the (meth) acrylic acid-modified rosin. 10 to 50% by weight is more preferable.

  As carboxylic acid compounds other than (meth) acrylic acid-modified rosin contained in the carboxylic acid component, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, Aliphatic dicarboxylic acids such as sebacic acid, azelaic acid, n-dodecyl succinic acid, n-dodecenyl succinic acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; Examples thereof include trivalent or higher polyvalent carboxylic acids such as merit acid and pyrrolemetic acid; anhydrides of these acids, alkyl (C1 to C3) esters, and the like. The acids as described above, and anhydrides and alkyl esters of these acids are collectively referred to herein as carboxylic acid compounds.

  The alcohol component preferably contains an aliphatic alcohol, particularly an aliphatic polyhydric alcohol. The aliphatic polyhydric alcohol is preferably a divalent to hexavalent aliphatic polyhydric alcohol, more preferably a divalent to trivalent aliphatic polyhydric alcohol, from the viewpoint of reactivity with a carboxylic acid component containing a modified rosin. The aliphatic polyhydric alcohol preferably contains an aliphatic polyhydric alcohol having 2 to 6 carbon atoms and a more compact molecular structure and high reactivity. Examples of the aliphatic polyhydric alcohol having 2 to 6 carbon atoms include ethylene glycol, neopentyl glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2 1,3-butanediol, pentaerythritol, trimethylolpropane, sorbitol, glycerin and the like, among which 1,2-propanediol, 1,3-propanediol and glycerin are preferable. The content of the aliphatic polyhydric alcohol having 2 to 6 carbon atoms is preferably 60 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and substantially 100 in the aliphatic polyhydric alcohol. More preferred is mol%.

  As alcohols other than aliphatic polyhydric alcohols contained in the alcohol component, polyoxypropylene-2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene-2,2-bis (4-hydroxyphenyl) Bisphenol A alkylene oxide adducts such as propane and other bisphenol A alkylene (2 to 3 carbon atoms) oxide adduct (average number of moles added 1 to 16), 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, and These alkylene (2 to 4 carbon atoms) oxide adducts (average added mole number 1 to 16) and the like can be mentioned.

  From the viewpoint of reactivity with the (meth) acrylic acid-modified rosin, the content of the aliphatic polyhydric alcohol is preferably 50 mol% or more, more preferably 60 mol% or more, and even more preferably 85 mol% or more in the alcohol component. Preferably, substantially 100 mol% is more preferable.

  From the viewpoint of improving offset resistance, the alcohol component contains a trihydric or higher polyhydric alcohol and / or the carboxylic acid component contains a trivalent or higher polyvalent carboxylic acid compound as long as the storage stability is not impaired. Is preferred. Since the (meth) acrylic acid-modified rosin used in the present invention is a rosin having two functional groups, trivalent or higher raw material monomers can be used without impairing the low-temperature fixability of the rosin. The offset resistance can be further improved while maintaining the properties. From these viewpoints, the content of the trivalent or higher polyvalent carboxylic acid compound is preferably 0.001 to 40 mol, more preferably 0.1 to 25 mol, and more preferably trivalent or higher polyhydric alcohol to 100 mol of the alcohol component. The content is preferably 0.001 to 40 mol%, more preferably 0.1 to 25 mol% in the alcohol component.

  In the trivalent or higher raw material monomer, as the trivalent or higher polyvalent carboxylic acid compound, trimellitic acid and its derivatives are preferable, and as the trivalent or higher polyhydric alcohol, glycerin, pentaerythritol, trimethylolpropane, sorbitol, And their alkylene (carbon number 2 to 4) oxide adducts (average number of added moles 1 to 16), etc., but among these, they not only serve as branching sites or act as crosslinking agents, but also have low temperature fixability. Glycerin, trimellitic acid and derivatives thereof are preferable because they are effective in improving the resistance.

  The condensation polymerization of the alcohol component and the carboxylic acid component is preferably performed in the presence of an esterification catalyst. Examples of the esterification catalyst in the present invention include Lewis acids such as p-toluenesulfonic acid, titanium compounds, tin (II) compounds having no Sn—C bond, and these may be used alone or both. Is used in combination. In the present invention, a titanium compound and / or a tin (II) compound having no Sn—C bond is preferred.

  As a titanium compound, the titanium compound which has a Ti-O bond is preferable, and the compound which has a C1-28 total carbon number alkoxy group, an alkenyloxy group, or an acyloxy group is more preferable.

Specific examples of titanium compounds include titanium diisopropylate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₃ H ₇ O) ₂ ], titanium diisopropylate bisdiethanolamate [Ti (C ₄ H ₁₀ O ₂ N) ₂ (C ₃ H ₇ O) ₂ ], titanium dipentylate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₅ H ₁₁ O) ₂ ], titanium diety rate bis triethanolaminate _{[Ti (C 6 H 14 O 3} N) 2 (C 2 H 5 O) 2 ], titanium dihydroxy octylate bis triethanolaminate _{[Ti (C 6 H 14 O 3} N) 2 (OHC 8 H ₁₆ O) ₂ ], titanium distearate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₁₈ H ₃₇ O) ₂ ], titanium triisopropylate triethanolamate [Ti (C _{6 H 14 O 3 N) 1 (} C 3 ₇ O) _3], titanium monopropylate tris (triethanolaminate) _{[Ti (C 6 H 14 O 3} N) 3 (C 3 H 7 O) 1 ], and the like, titanium diisopropylate Among these Preferred are rate bistriethanolamate, titanium diisopropylate bisdiethanolamate and titanium dipentylate bistriethanolamate, which are available as commercial products from Matsumoto Trading Co., Ltd., for example.

Specific examples of other preferable titanium compounds include tetra-n-butyl titanate [Ti (C ₄ H ₉ O) ₄ ], tetrapropyl titanate [Ti (C ₃ H ₇ O) ₄ ], tetrastearyl titanate [Ti ( C ₁₈ H ₃₇ O) ₄ ], tetramyristyl titanate [Ti (C ₁₄ H ₂₉ O) ₄ ], tetraoctyl titanate [Ti (C ₈ H ₁₇ O) ₄ ], dioctyl dihydroxyoctyl titanate [Ti (C ₈ H ₁₇ O) ₂ (OHC ₈ H ₁₆ O) ₂ ], dimyristyl dioctyl titanate [Ti (C ₁₄ H ₂₉ O) ₂ (C ₈ H ₁₇ O) ₂ ] and the like. Among these, tetrastearyl titanate, tetra Myristyl titanate, tetraoctyl titanate and dioctyl dihydroxy octyl titanate are preferred. These can be obtained, for example, by reacting a titanium halide with a corresponding alcohol, or can be obtained as a commercial product such as Nisso.

  The amount of the titanium compound present is preferably 0.01 to 1.0 part by weight and more preferably 0.1 to 0.7 part by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component.

  Examples of the tin (II) compound having no Sn—C bond include a tin (II) compound having a Sn—O bond, a tin (II) compound having a Sn—X (X represents a halogen atom) bond, and the like. Preferably, a tin (II) compound having a Sn—O bond is more preferable.

Examples of tin (II) compounds having a Sn-O bond include tin (II) oxalate, tin (II) diacetate, tin (II) dioctanoate, tin (II) dilaurate, tin (II) distearate, diolein Carboxylic acid tin (II) having a carboxylic acid group of 2 to 28 carbon atoms such as tin (II) acid; A dialkoxytin (II) having an alkoxy group having 2 to 28 carbon atoms; a tin (II) compound in which tin (II) oxide, tin (II) sulfate or the like has a Sn-X (X represents a halogen atom) bond Examples thereof include tin (II) halides such as tin (II) chloride and tin (II) bromide, and among these, (R ¹ COO) ₂ Sn from the viewpoint of the charge rising effect and catalytic ability. (Wherein R ¹ represents an alkyl or alkenyl group having 5 to 19 carbon atoms) fatty acid tin (II), (R ² O) ₂ Sn (where R ² is an alkyl having 6 to 20 carbon atoms) Base Or dialkoxytin (II) represented by SnO and tin (II) oxide represented by SnO are preferred, and fatty acid tin (II) and tin oxide represented by (R ¹ COO) ₂ Sn ( II) is more preferred, and tin (II) dioctanoate, tin (II) distearate and tin (II) oxide are more preferred.

  The abundance of the tin (II) compound is preferably 0.01 to 1.0 part by weight, more preferably 0.1 to 0.7 part by weight, based on 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component.

  When the titanium compound and the tin (II) compound are used in combination, the total amount of the titanium compound and the tin (II) compound is preferably 0.01 to 1.0 part by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component, 0.1-0.7 weight part is more preferable.

  The polycondensation of the alcohol component and the carboxylic acid component can be performed, for example, at a temperature of 180 to 250 ° C. in an inert gas atmosphere in the presence of the esterification catalyst.

  The difference in softening point between the two types of polyester resins is 10 ° C. or more from the viewpoint of enhancing the dispersibility of the internal additive and enhancing the effect on fixing property and offset resistance, particularly high-temperature offset resistance. In achromatic toners such as black toner, the temperature is preferably 10 to 60 ° C., more preferably 20 to 50 ° C., from the viewpoint of suppressing gloss. In addition, in chromatic color toners such as yellow toner, magenta toner, and cyan toner, 10 to 30 ° C. is preferable and 15 to 30 ° C. is more preferable from the viewpoint of improving gloss. The softening point of the polyester resin (A) having a lower softening point is preferably from 80 to 120 ° C, more preferably from 90 to 110 ° C, from the viewpoint of fixability. On the other hand, the softening point of the polyester resin (B) having a higher softening point is preferably from 100 to 180 ° C, more preferably from 120 to 180 ° C, and even more preferably from 120 to 160 ° C, from the viewpoint of high temperature offset resistance.

  The glass transition point of the polyester resin (A) and the polyester resin (B) is preferably 45 to 75 ° C, and more preferably 50 to 70 ° C, from the viewpoints of fixability, storage stability and durability. From the viewpoint of chargeability and environmental stability, the acid value is preferably 1 to 80 mgKOH / g, more preferably 5 to 60 mgKOH / g, further preferably 5 to 50 mgKOH / g, and the hydroxyl value is 1 to 80 mgKOH / g. Preferably, 8 to 50 mgKOH / g is more preferable, and 8 to 40 mgKOH / g is more preferable.

  In the polyester resin (A) and the polyester resin (B), the content of low molecular weight components having a molecular weight of 500 or less due to residual monomer components and oligomer components from the viewpoint of low-temperature fixability, offset resistance and storage stability However, in the polyester resin, it is preferably 12% or less, more preferably 10% or less, further preferably 9% or less, and further preferably 8% or less. The content of the low molecular weight component can be reduced by a method such as increasing the degree of rosin modification with (meth) acrylic acid. The content of the low molecular weight component depends on the area ratio of the molecular weight measured by gel permeation chromatography (GPC) described later.

  In the present invention, the polyester units in the polyester resins (A) and (B) are preferably amorphous different from crystallinity. In this specification, an amorphous resin refers to a resin having a difference between the softening point and the glass transition point (Tg) of 30 ° C. or more.

  The weight ratio of the polyester-based resin (A) to the polyester-based resin (B) is preferably 10/90 to 90/10, more preferably 20/80 to 80/20, from the viewpoint of fixability and durability. 70 to 70/30 is more preferable.

  In the present invention, when the binder resin is composed of three or more polyester resins, any two resins having a total content in the binder resin of 50% by weight or more are polyester resins ( What is necessary is just to satisfy the relationship between the softening point of A) and a polyester-type resin (B). Therefore, the binder resin includes polyester resins not corresponding to the polyester resin (A) and the polyester resin (B) within a range not impairing the effects of the present invention, for example, known binder resins such as styrene- Other resins such as vinyl resins such as acrylic resins, epoxy resins, polycarbonates and polyurethanes may be used in combination, but the total content of polyester resins (A) and polyester resins (B) is the binder resin Among them, 70% by weight or more is preferable, 80% by weight or more is more preferable, 90% by weight or more is further preferable, and substantially 100% by weight is further preferable.

  Furthermore, from the viewpoint of low-temperature fixability, offset resistance, durability, and storage stability, the content of the resin derived from the (meth) acrylic acid-modified rosin in the binder resin is preferably 70% by weight or more, and 80% by weight or more. Is more preferable, 90% by weight or more is more preferable, and substantially 100% by weight is further preferable.

  In the present invention, the polyester resin means a resin having a polyester unit. The polyester unit refers to a portion having a polyester structure, and the polyester resin includes not only polyester but also polyester modified to such an extent that the properties are not substantially impaired. Both (A) and (B) are preferably polyesters. Examples of the modified polyester include grafting and blocking with phenol, urethane, epoxy and the like by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, and the like. And a composite resin having two or more types of resin units including a polyester unit.

  The composite resin is preferably a resin having a polyester unit and an addition polymerization resin unit such as a vinyl resin.

  Examples of the raw material monomer for the polyester unit include the same alcohol component and carboxylic acid component as the raw material monomer for the polyester.

  On the other hand, as a raw material monomer of the vinyl resin unit, styrene compounds such as styrene and α-methylstyrene; ethylenically unsaturated monoolefins such as ethylene and propylene; diolefins such as butadiene; halovinyls such as vinyl chloride; Vinyl esters such as vinyl acetate and vinyl propionate; alkyl (1 to 18 carbon atoms) esters of (meth) acrylic acid, esters of ethylenic monocarboxylic acids such as dimethylaminoethyl (meth) acrylate; vinyl methyl ether, etc. Vinyl ethers such as vinylidene chloride, vinylidene halides such as vinylidene chloride, N-vinyl compounds such as N-vinylpyrrolidone, and the like. Among these, long-chain alkyls of styrene, 2-ethylhexyl acrylate, butyl acrylate and acrylic acid ( C12-12) ester is preferred From the viewpoint of chargeability, styrene, from the viewpoint of fixability and adjustment of the glass transition point, alkyl esters of (meth) acrylic acid are preferred. The content of styrene is preferably 50 to 90% by weight and more preferably 75 to 85% by weight in the raw material monomer of the vinyl resin. The monomer weight ratio of styrene to the alkyl ester of (meth) acrylic acid (styrene / alkyl ester of (meth) acrylic acid) is preferably 50/50 to 95/5, and more preferably 70/30 to 95/5.

  In addition, you may use a polymerization initiator, a crosslinking agent, etc. for the addition polymerization of the raw material monomer of a vinyl-type resin unit as needed.

  In the present invention, the weight ratio of the raw material monomer of the polyester unit to the raw material monomer of the addition polymerization resin unit (raw material monomer of the polyester unit / raw material monomer of the addition polymerization resin unit) is such that the continuous phase is the polyester unit and the dispersed phase Is preferably an addition polymerization type resin unit, 50/50 to 95/5 is preferable, and 60/40 to 95/5 is more preferable.

  In the present invention, the composite resin is a compound capable of reacting with both the raw material monomer of the polyester unit and the raw material monomer of the addition polymerization resin unit, as well as both the raw material monomer of the polyester unit and the raw material monomer of the addition polymerization resin unit (both A resin (hybrid resin) obtained using a reactive monomer) is preferable.

  As the both reactive monomers, at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group and a secondary amino group in the molecule, and an ethylenically unsaturated bond A compound having the above formula is preferred, and by using such a bireactive monomer, the dispersibility of the resin to be the dispersed phase can be further improved. Specific examples of the both reactive monomers include, for example, acrylic acid, fumaric acid, methacrylic acid, citraconic acid, maleic acid, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, and carboxylic acids thereof. Derivatives such as anhydrides and alkyl (1 to 2 carbon atoms) esters may be mentioned, and among these, acrylic acid, methacrylic acid, fumaric acid, maleic acid and derivatives of these carboxylic acids are preferred from the viewpoint of reactivity.

  In the present invention, among the two reactive monomers, a monomer having two or more functional groups (polycarboxylic acid or the like) and a derivative thereof are used as a raw material monomer for the polyester unit as a monomer having one functional group (monocarboxylic acid or the like) and The derivative is treated as a raw material monomer for the addition polymerization resin unit. The amount of the both reactive monomers used is preferably 1 to 30 moles with respect to 100 moles of the raw material monomer of the polyester unit excluding the both reactive monomers, and from the viewpoint of further enhancing the dispersibility of the addition polymerization resin unit. In the process of producing the resin, in the method of reacting at a high temperature after the addition polymerization reaction, 1.5 to 20 mol is more preferable, and 2 to 10 mol is more preferable. After the addition polymerization reaction, the both reactivity is maintained while keeping the reaction temperature constant. In the method using a large amount of monomer, 4 to 15 mol is more preferable, and 4 to 10 mol is more preferable.

  In the present invention, from the viewpoint of uniformity of the polyester unit and the addition polymerization resin unit, the composite resin is prepared by previously mixing the raw material monomer of the polyester unit and the raw material monomer of the addition polymerization resin unit, and performing the condensation polymerization reaction and the addition polymerization reaction. Is preferably a resin obtained by performing in parallel in the same reaction vessel, and when the composite resin is a hybrid resin obtained by using both reactive monomers, the raw material monomer of the condensation polymerization resin unit In addition, it is preferable to use a resin obtained by previously mixing a mixture of monomers as raw materials for the addition polymerization resin unit and the both reactive monomers and performing the condensation polymerization reaction and the addition polymerization reaction in parallel in the same reaction vessel.

  In the present invention, the progress and completion of the condensation polymerization reaction and the addition polymerization reaction do not need to be simultaneous in time, and the reaction temperature and time are appropriately selected according to each reaction mechanism to allow the reaction to proceed and complete. Just do it. For example, the raw material monomer of the polyester unit, the raw material monomer of the addition polymerization resin unit, the bireactive monomer, etc. are mixed, and first, polycondensation is carried out mainly by the addition polymerization reaction at a temperature condition suitable for the addition polymerization reaction, for example, 50 to 180 ° C. After forming an addition polymerization resin having a functional group capable of reaction, the reaction temperature is then raised to a temperature condition suitable for the condensation polymerization reaction, for example, 190 to 270 ° C. The method of forming resin is mentioned.

  The toner of the present invention further includes a colorant, a release agent, a charge control agent, a magnetic powder, a fluidity improver, a conductivity modifier, an extender pigment, a reinforcing filler such as a fibrous substance, an antioxidant, and an aging agent. Additives such as an inhibitor and a cleaning property improver may be appropriately contained.

  As the colorant, all of dyes and pigments used as toner colorants can be used, and carbon black; I. C.I. Pigment Yellow 1, 3, 74, 97, 98, etc. acetoacetic acid arylamide monoazo yellow pigments; I. C.I. Pigment Yellow 12, 13, 14, 17, etc. acetoacetic acid arylamide disazo yellow pigments; I. Pigment Yellow 93, 95, and other polyazo yellow pigments; C.I. I. Pigment yellow 180; C.I. I. Pigment yellow 185; C.I. I. Solvent Yellow 19, 77, 79, C.I. I. Yellow dyes such as disperse yellow 164; I. CI Pigment Red 48, 49: 1, 53: 1, 57, 57: 1, 81, 122, 184, 5 and the like; I. Red dyes such as Solvent Red 49, 52, 58, 8; I. Blue dyes and pigments of copper phthalocyanine and its derivatives such as CI Pigment Blue 15: 3; I. Pigment Green 7 and 36 (phthalocyanine green), and the like. These may be used alone or as a mixture of two or more thereof. Either color toner or full color toner may be used. The content of the colorant is preferably 1 to 15 parts by weight with respect to 100 parts by weight of the total amount of the vinyl resin and polyester in the dispersion.

  As release agents, low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicones; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide and stearic acid amide; carnauba wax, rice wax and candelilla Plant waxes such as wax, tree wax and jojoba oil; animal waxes such as beeswax; mineral and petroleum waxes such as montan wax, ozokerite, ceresin, paraffin lux, microcrystalline wax, and Fischer-Tropsch wax. These release agents may be used alone or in combination of two or more.

  The melting point of the release agent is preferably from 50 to 120 ° C., more preferably below the softening point of the binder resin, in consideration of the blocking resistance and the influence on the low-temperature fixability of the binder resin. The content of the release agent is preferably 1 to 20 parts by weight, more preferably 2 to 15 parts per 100 parts by weight of the binder resin in consideration of the effect on the low temperature offset and the influence on the chargeability. Part by weight, more preferably 2 to 10 parts by weight.

  As the charge control agent, any one of negative chargeability and positive chargeability can be used. Examples of the negatively chargeable charge control agent include metal-containing azo dyes, copper phthalocyanine dyes, metal complexes of salicylic acid alkyl derivatives, and nitroimidazole derivatives. Examples of the positively chargeable charge control agent include nigrosine dyes, triphenylmethane dyes, quaternary ammonium salt compounds, polyamine resins, and imidazole derivatives. Also, a polymer type such as a resin can be used. The content of the charge control agent is preferably 0.1 to 8 parts by weight and more preferably 0.2 to 5 parts by weight with respect to 100 parts by weight of the binder resin.

The electrophotographic toner of the present invention may be a toner obtained by any conventionally known method such as a melt-kneading method, an emulsion phase inversion method, or a polymerization method. From the viewpoint, a pulverized toner obtained by a melt-kneading method including a step of melt-kneading a binder resin, that is, at least two polyester resins having different softening points, is preferable. In the case of the pulverized toner by the melt-kneading method, specifically, the additives such as the binder resin, the colorant, and the release agent are mixed with a mixer such as a Henschel mixer, and then the sealed kneader, uniaxial or biaxial The toner can be produced by melt-kneading with an extruder, open roll type kneader, etc., cooling, pulverizing and classifying. The volume median particle size (D ₅₀ ) of the toner is preferably 3 to 15 μm, more preferably 4 to 10 μm. In the present specification, the volume-median particle size (D ₅₀ ) means a particle size at which the cumulative volume frequency calculated by the volume fraction is 50% when calculated from the smaller particle size.

  Further, the toner of the present invention may be externally treated with an external additive such as inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide and zinc oxide, and organic fine particles such as resin fine particles. Good.

As the external additive, silica having a small specific gravity is preferable from the viewpoint of preventing embedding. From the viewpoint of environmental stability, the silica is preferably hydrophobic silica that has been subjected to a hydrophobic treatment. The method for hydrophobizing is not particularly limited, and examples of the hydrophobizing agent include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), silicone oil, methyltriethoxysilane, and the like. The treatment amount of the hydrophobizing agent is preferably 1 to 7 mg / m ² per surface area of the inorganic fine particles.

  The number average particle diameter of the external additive is preferably from 3 to 300 nm, more preferably from 5 to 100 nm, from the viewpoint of chargeability and prevention of scratches on the photoreceptor.

  The content of the external additive is preferably 0.01 to 10 parts by weight and more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the toner base particles.

  The toner of the present invention can be used as a one-component developing toner or as a two-component developer mixed with a carrier.

In the present invention, from the viewpoint of image characteristics, it is preferable to use a carrier with low saturation magnetization that weakens the area around the magnetic brush. Saturation magnetization of the carrier is preferably ^{40~100Am 2 / kg, 50~90Am 2 /} kg is more preferable. The saturation magnetization is preferably 100 Am ² / kg or less from the viewpoint of adjusting the hardness of the magnetic brush and maintaining gradation reproducibility, and preferably 40 Am ² / kg or more from the viewpoint of preventing carrier adhesion and toner scattering.

  As the core material of the carrier, those made of known materials can be used without particular limitation, for example, ferromagnetic metals such as iron, cobalt, nickel, magnetite, hematite, ferrite, copper-zinc-magnesium ferrite, Examples include alloys and compounds such as manganese ferrite and magnesium ferrite, and glass beads. Among these, iron powder, magnetite, ferrite, copper-zinc-magnesium ferrite, manganese ferrite, and magnesium ferrite are preferable from the viewpoint of chargeability. From the viewpoint of image quality, ferrite, copper-zinc-magnesium ferrite, manganese ferrite and magnesium ferrite are more preferable.

  The surface of the carrier is preferably coated with a resin from the viewpoint of reducing carrier contamination. The resin that coats the carrier surface varies depending on the toner material. For example, fluororesin such as polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin such as polydimethylsiloxane, polyester, styrenic resin, Acrylic resins, polyamides, polyvinyl butyral, amino acrylate resins, and the like can be used, and these can be used alone or in combination of two or more. However, when the toner is negatively charged, the chargeability and surface From the viewpoint of energy, a silicone resin is preferable. The method for coating the core material with the resin is not particularly limited, for example, a method in which a coating material such as a resin is dissolved or suspended in a solvent and applied to the core material, or a method of simply mixing with a powder.

  In the two-component developer of the present invention obtained by mixing the toner and the carrier, the toner to carrier weight ratio (toner / carrier) is preferably 1/99 to 10/90, and 5/95 to 7/93. More preferred.

[Softening point of resin]
Using a flow tester (Shimadzu Corporation, CFT-500D), a 1 g sample is heated at a heating rate of 6 ° C / min, and a 1.96 MPa load is applied by a plunger and extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. . The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[Softening point of rosin]
(1) Sample preparation 10g of rosin is melted on a hot plate at 170 ° C for 2 hours. After that, it is naturally cooled for 1 hour in an open state at a temperature of 25 ° C. and a relative humidity of 50%, and then ground for 10 seconds in a coffee mill (National MK-61M).
(2) Measurement Using a flow tester (Shimadzu Corporation, CFT-500D), a 1g sample was heated at a heating rate of 6 ° C / min, and a load of 1.96MPa was applied by a plunger, with a diameter of 1mm and a length of 1mm. Extrude from nozzle. The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[Glass transition point of resin and rosin]
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), weigh 0.01 to 0.02 g of the sample into an aluminum pan, raise the temperature to 200 ° C, and from that temperature to 0 ° C at a rate of 10 ° C / min. The temperature of the cooled sample is raised at a heating rate of 10 ° C / min, and the temperature at the intersection of the base line extension below the maximum peak temperature of endotherm and the tangent that indicates the maximum slope from the peak rise to the peak apex To do.

[Acid value of resin and rosin]
Measured according to the method of JIS K0070. However, only the measurement solvent was changed from the mixed solvent of ethanol and ether specified in JIS K0070 to the mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

[Hydroxyl value of the resin]
Measured according to the method of JIS K0070.

[Content of low molecular weight component having a molecular weight of 500 or less]
The molecular weight distribution is measured by gel permeation chromatography (GPC). Add 10 ml of tetrahydrofuran to 30 mg of toner, mix for 1 hour with a ball mill, and filter using a fluororesin filter “FP-200” (manufactured by Sumitomo Electric Industries, Ltd.) with a pore size of 2 μm to remove insoluble components and prepare a sample solution To do.

Tetrahydrofuran is flowed as an eluent at a flow rate of 1 ml / min, the column is stabilized in a constant temperature bath at 40 ° C., and 100 μl of the sample solution is injected to perform measurement. In addition, “GMHLX + G3000HXL” (manufactured by Tosoh Corp.) is used as an analytical column, and several types of monodisperse polystyrene (2.63 × 10 ³ , 2.06 × 10 ⁴ , 1.02 × 10 ⁴ manufactured by Tosoh Corp.) are used for the molecular weight calibration curve. ^5. Prepare 2.10 × 10 ³ , 7.00 × 10 ³ , 5.04 × 10 ⁴ ) manufactured by GL Science as standard samples.

  The content (%) of low molecular weight components having a molecular weight of 500 or less is the ratio of the area of the corresponding area in the chart area obtained by the RI (refractive index) detector to the total chart area (area of the corresponding area / total chart area). ).

[SP value of rosin]
After pouring 2.1 g of the molten sample into a predetermined ring, the sample is cooled to room temperature and then measured under the following conditions based on JIS B7410.
Measuring machine: Ring-and-ball automatic softening point tester ASP-MGK2 (manufactured by Meitec)
Temperature increase rate: 5 ℃ / min
Temperature rise start temperature: 40 ℃
Measuring solvent: Glycerin

(Degree of (meth) acrylic acid modification of rosin)
Formula (A):

(Wherein X ₁ is the SP value of (meth) acrylic acid-modified rosin for calculating the degree of modification, and X ₂ is (meth) acrylic acid-modified obtained by reacting 1 mol of (meth) acrylic acid with 1 mol of rosin. Saturated SP value of rosin, Y indicates SP value of rosin)
Calculated by The saturated SP value means the SP value when the reaction of (meth) acrylic acid and rosin is allowed to react until the SP value of the obtained (meth) acrylic acid-modified rosin reaches a saturation value. The molecular weight of the rosin 1 mol, when the acid value x (mg KOH / g), potassium hydroxide relative to the rosin 1 g (molecular weight: 56.1) that is xmg (x × 10 ^-3 g) reaction Therefore, formula (B):
Molecular weight = 56100 ÷ x (B)
Can be calculated.

[Melting point of release agent]
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), the temperature was raised to 200 ° C, and the sample was cooled to 0 ° C at a temperature drop rate of 10 ° C / min. The maximum peak temperature of heat of fusion is taken as the melting point.

[Number average particle diameter of external additives]
Obtained from the following formula.
Number average particle diameter (nm) = 6 / (ρ × specific surface area (m ² / g)) × 1000
In the formula, ρ is the specific gravity of the inorganic fine powder or the external additive, and the specific surface area is the original BET specific surface area obtained by the nitrogen adsorption method of the raw material, or in the case of the external additive, before the hydrophobic treatment. is there. For example, the specific gravity of silica is 2.2 and the specific gravity of titanium oxide is 4.2.
The above formula is assumed to be a sphere having a particle size R,
BET specific surface area = S x (1 / m)
m (weight of particle) = 4/3 x π x (R / 2) ³ x density
S (surface area) = 4π (R / 2) ²
Is an expression obtained from

[Volume-median particle diameter of toner (D ₅₀ )]
Measuring machine: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 100μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (Beckman Coulter)
Electrolyte: Isoton II (Beckman Coulter, Inc.)
Dispersion: Emulgen 109P (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB: 13.6) is dissolved in the electrolytic solution to a concentration of 5% by weight to obtain a dispersion.
Dispersion conditions: 10 mg of a measurement sample is added to 5 ml of the dispersion, and dispersed for 1 minute with an ultrasonic disperser, then 25 ml of an electrolyte is added, and further dispersed for 1 minute with an ultrasonic disperser. Prepare a dispersion.
Measurement conditions: After adjusting the particle size of 30,000 particles to a concentration that can be measured in 20 seconds by adding the sample dispersion to 100 ml of the electrolyte solution, 30,000 particles are measured, Determine the volume median particle size (D ₅₀ ).

<Purification example of rosin>
1000 g of tall rosin was added to a 2000 ml-distillation flask equipped with a fractionation tube, a reflux condenser and a receiver, distilled under a reduced pressure of 1 kPa, and the distillate at 195 to 250 ° C. was collected as the main fraction. . Hereinafter, tall rosin subjected to purification is referred to as unpurified rosin, and rosin collected as a main fraction is referred to as purified rosin.

  20 g of rosin was pulverized for 5 seconds with a coffee mill (National MK-61M), and 0.5 g was measured in a headspace vial (20 ml) after passing through a 1 mm sieve. Table 1 shows the results of sampling the headspace gas and analyzing the unpurified rosin and impurities in the purified rosin by the headspace GC-MS method.

[Measurement conditions for headspace GC-MS method]
A. Headspace sampler (Agilent, HP7694)
Sample temperature: 200 ℃
Loop temperature: 200 ° C
Transfer line temperature: 200 ° C
Sample heating equilibration time: 30min
Bayal pressurized gas: Helium (He)
Bayal pressurization time: 0.3min
Loop filling time: 0.03min
Loop equilibration time: 0.3min
Injection time: 1min

B. GC (Gas Chromatography) (Agilent, HP6890)
Analytical column: DB-1 (60m-320μm-5μm)
Carrier: Helium (He)
Flow rate condition: 1ml / min
Inlet temperature: 210 ° C
Column head pressure: 34.2kPa
Injection mode: split
Split ratio: 10: 1
Oven temperature condition: 45 ℃ (3min) -10 ℃ / min-280 ℃ (15min)

C. MS (mass spectrometry) (Agilent, HP5973)
Ionization method: EI (electron ionization) method Interface temperature: 280 ℃
Ion source temperature: 230 ° C
Quadrupole temperature: 150 ° C
Detection mode: Scan 29-350m / s

<Measurement of saturation SP value of acrylic acid-modified rosin using unpurified rosin>
To a 1000 ml flask equipped with a fractionation tube, reflux condenser and receiver, 332 g (1 mol) of unpurified rosin (SP value: 77.0 ° C) and 72 g (1 mol) of acrylic acid were added. After heating up over 8 hours and confirming that the SP value did not increase at 230 ° C, unreacted acrylic acid and low-boiling substances were distilled off under reduced pressure at 230 ° C and 5.3 kPa. A modified rosin was obtained. The SP value of the resulting acrylic acid-modified rosin, that is, the saturated SP value of the acrylic acid-modified rosin using unpurified rosin was 110.1 ° C.

<Measurement of saturation SP value of acrylic acid-modified rosin using purified rosin>
Purified rosin (SP value: 76.8 ° C) 338g (1 mol) and acrylic acid 72g (1 mol) and acrylic acid 72g (1 mol) were added to a 1000ml flask equipped with a fractionation tube, reflux condenser and receiver. After increasing the temperature over time and confirming that the SP value did not increase at 230 ° C, unreacted acrylic acid and low-boiling substances were distilled off at 230 ° C under a reduced pressure of 5.3kPa to modify acrylic acid. I got rosin. The SP value of the obtained acrylic acid-modified rosin, that is, the saturated SP value of the acrylic acid-modified rosin using purified rosin was 110.4 ° C.

<Production Example 1 of Acrylic Acid-Modified Rosin>
Purified rosin (SP value: 76.8 ° C) 6084 g (18 mol) and acrylic acid 907.9 g (12.6 mol) were added to a 10 L flask equipped with a fractionation tube, reflux condenser and receiver, and the temperature was increased from 160 ° C to 220 ° C. After heating for 8 hours and reacting at 220 ° C. for 2 hours, distillation was further performed under reduced pressure at 220 ° C. and 5.3 kPa to obtain acrylic acid-modified rosin A. The acrylic acid-modified rosin A had an SP value of 110.4 ° C., a glass transition point of 57.1 ° C., and an acrylic acid modification degree of 100.

<Production Example 2 of acrylic acid-modified rosin>
Purified rosin (SP value: 76.8 ° C) 6084 g (18 mol) and acrylic acid 648.5 g (9.0 mol) were added to a 10 L flask equipped with a fractionation tube, a reflux condenser and a receiver. After raising the temperature over 8 hours and reacting at 220 ° C. for 2 hours, distillation was further performed under reduced pressure at 220 ° C. and 5.3 kPa to obtain acrylic acid-modified rosin B. The acrylic acid-modified rosin B had an SP value of 99.1 ° C., a glass transition point of 53.2 ° C., and an acrylic acid modification degree of 66.

<Production Example 3 of Acrylic Acid-Modified Rosin>
Unpurified rosin (SP value: 77.0 ° C) 5976 g (18 mol) and acrylic acid 907.6 g (12.6 mol) were added to a 10 L flask equipped with a fractionation tube, a reflux condenser and a receiver. The mixture was heated for 8 hours, reacted at 250 ° C. for 2 hours, and further distilled under reduced pressure at 250 ° C. and 5.3 kPa to obtain acrylic acid-modified rosin C. The acrylic acid-modified rosin C had an SP value of 110.1 ° C., a glass transition point of 54.5 ° C., and an acrylic acid modification degree of 100.

<Resin production examples 1-6, 8-12>
A fractionation tube with 98 ° C. warm water flowing, equipped with a reflux condenser tube with the alcohol component, carboxylic acid component other than trimellitic anhydride and esterification catalyst shown in Tables 2 and 3 and water with cold water at room temperature. , Put into a 5 liter four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple, conduct a polycondensation reaction at 160 ° C for 2 hours in a nitrogen atmosphere, and then to 210 ° C over 6 hours The temperature was raised, and then the reaction was carried out at 66 kPa for 1 hour. After cooling to 200 ° C, the trimellitic anhydride shown in Tables 2 and 3 was added and reacted at normal pressure (101.3 kPa) for 1 hour, then the temperature was raised to 210 ° C and the desired softening point was reached at 40 kPa. The reaction was carried out until it reached polyester (resins 1-6, 8-12).

<Resin production example 7>
Equipped with reflux condenser, nitrogen inlet, dehydrator, dropping funnel, stirrer, and thermocouple with alcohol components, carboxylic acid components other than trimellitic anhydride, and esterification catalyst shown in Table 3 through cold water at room temperature The styrene, 2-ethylhexyl acrylate, acrylic acid and di-t-butyl peroxide shown in Table 3 were added from a dropping funnel over 2 hours at 150 ° C. in a nitrogen atmosphere. After dropping the mixture, an aging reaction was performed at 150 ° C. for 2 hours. Thereafter, the temperature was raised to 230 ° C. and a condensation polymerization reaction was carried out for 8 hours. After cooling to 210 ° C, trimellitic anhydride shown in Table 3 was added and reacted at normal pressure (101.3 kPa) for 1 hour, then heated to 210 ° C and reached the desired softening point at 40 kPa. The hybrid resin (resin 7) comprising a polyester unit and a vinyl resin unit was obtained.

<Examples 1 to 7 and Comparative Examples 1 and 2>
Binder resin shown in Table 4, carbon black "MOGUL L" (Cabot) 4 parts by weight, negative charge control agent "Bontron S-34" (Orient Chemical Industries) 1 part by weight and polypropylene wax "NP" -105 "(Mitsui Chemicals, melting point: 105 ° C) 1 part by weight was mixed thoroughly with a Henschel mixer, then using a co-rotating twin screw extruder, the roll rotation speed was 200r / min, and the heating temperature in the roll was Melt-kneaded at 80 ° C. The obtained melt-kneaded product was cooled and coarsely pulverized, then pulverized with a jet mill and classified to obtain a powder having a volume median particle size (D ₅₀ ) of 8.0 μm.

  To 100 parts by weight of the obtained powder, 1.0 part by weight of “Aerosil R-972” (manufactured by Nippon Aerosil Co., Ltd., hydrophobizing agent: DMDS, number average particle diameter: 16 nm) was added as an external additive. The toner was obtained by mixing.

<Test Example 1 [Low-temperature fixability and offset resistance]>
Mount the toner on the printer “OKI Microline 18” (Casio Computer Co., Ltd., Oki Data Co., Ltd., fixing: contact fixing method, developing method: non-magnetic one-component developing method), and adjust the toner adhesion amount to 0.6 mg / cm ² An unfixed image was obtained. The fixing machine (fixing speed: 300 mm / s) was improved so that the fixing machine of the contact fixing type copier `` AR-505 '' (manufactured by Sharp Corporation) can be fixed outside the device. The fixing roll was fixed by fixing the unfixed image while increasing the temperature of the fixing roll from 100 ° C. to 240 ° C. in 5 ° C. increments.

  The image obtained at each fixing temperature was pasted with `` UNICEF Cellophane '' (Mitsubishi Pencil Co., Ltd., width 18 mm, JISZ-1522), passed through the fixing roll of the fixing machine set to 30 ° C., and then the tape was applied. The optical reflection density before and after peeling and tape peeling was measured using a reflection densitometer “RD-915” (manufactured by Macbeth). The fixing roller temperature at which the ratio between the two (after peeling / before peeling) first exceeded 90% was set as the minimum fixing temperature, and the low-temperature fixing property was evaluated according to the following evaluation criteria. At the same time, the occurrence of hot offset was visually observed, and the offset resistance was evaluated according to the following evaluation criteria. The results are shown in Table 4.

[Evaluation criteria for low-temperature fixability]
◎: Minimum fixing temperature is less than 150 ° C ○: Minimum fixing temperature is 150 ° C or more and less than 170 ° C △: Minimum fixing temperature is 170 ° C or more and less than 180 ° C ×: Minimum fixing temperature is 180 ° C or more

[Evaluation criteria for offset resistance]
A: Hot offset does not occur even at 240 ° C.
○: Hot offset occurs at 220 ° C or higher and 240 ° C or lower.
Δ: Hot offset occurs at 190 ° C or higher and lower than 220 ° C.
X: Hot offset occurs below 190 ° C.

<Test Example 2 [Durability]>
Toner is mounted on the printer “OKI Microline 18” (Casio Computer Co., Ltd., Oki Data Co., Ltd., fixing: contact fixing method, developing method: non-magnetic one-component developing method) under conditions of 25 ° C. and relative humidity 60% Diagonal stripe patterns with a blackening rate of 10% were continuously printed and subjected to a printing durability test. A solid image of 3 cm × 3 cm was printed during initial printing (100 sheets) and after printing (10000 sheets), and the image density was measured. Note that the image density is the average value of the image densities at the four corners and the center of the solid image. Based on the difference in image density during initial printing and after printing, durability was evaluated according to the following evaluation criteria. The results are shown in Table 4.

  For measurement of image density, “GRETAG SPM50” (manufactured by GretagMacbeth AG) was used. Calibration was performed using absolute white as a white reference, and a calibration card “GretagMacbeth Density Calibration Reference” (Type: 47B / P, Density Standard: DIN 16536, Filter: Polarized) was used for calibration.

(Evaluation criteria)
The difference in image density after initial printing and after printing
◎: Less than 0.1 ○: 0.1 or more, less than 0.2 △: 0.2 or more, less than 0.3 ×: 0.3 or more

<Test Example 3 [filming resistance]>
Toner is mounted on the printer “Page Presto N-4” (Casio Computer Co., Ltd., fixing: contact fixing method, developing method: non-magnetic one-component developing method, developing roll diameter: 2.3 cm), 25 ° C., relative humidity 60% Under these conditions, a diagonal stripe pattern with a blackening rate of 5.5% was continuously printed, and a filming test was performed. In the middle, a black solid image was printed every 500 sheets, the presence or absence of streaks on the image was visually confirmed, and printing was stopped when the occurrence of streaks was confirmed. The filming test was performed up to 10000 sheets, and the durability was evaluated according to the following criteria, with the number of printed sheets at the time when the occurrence of streaks was confirmed on the image as the number of printed sheets. The results are shown in Table 4.

〔Evaluation criteria〕
◎: There is no streaking up to 10000 sheets, and the number of printing sheets is 10,000 sheets or more. ○: The number of printing sheets is 5000 sheets or more and less than 10,000 sheets. △: The printing sheet number is 2000 sheets or more and less than 5000 sheets. Less than 2000

<Test Example 4 [Preservation]>
Prepare two samples of 4 g of toner in an open cylindrical container with a diameter of 5 cm and a height of 2 cm. One is in an environment with a temperature of 40 ° C and a relative humidity of 60%, and the other is at a temperature of 55 ° C and a relative humidity of 60. % Environment for 72 hours. After leaving, the container containing the toner was shaken lightly to visually observe the presence or absence of toner aggregation, and the storage stability was evaluated according to the following evaluation criteria. The results are shown in Table 4.

〔Evaluation criteria〕
A: No aggregation of toner is observed at any temperature of 40 ° C. and 55 ° C.
○: No aggregation of toner is observed under an environment of 40 ° C., but slight aggregation particles of the toner are observed under an environment of 55 ° C.
Δ: Toner agglomeration particles are slightly observed under an environment of 40 ° C., and aggregation is clearly observed under an environment of 55 ° C.
X: Aggregation is clearly observed in any environment of 40 ° C and 55 ° C.

<Test Example 5 [Odor]>
Weigh 20g of toner in an aluminum foil cup (Teraoka Co., Ltd .; FM-409 (main unit)) and leave it on a hot plate heated to 150 ° C for 30 minutes. According to the evaluation. The results are shown in Table 4.

〔Evaluation criteria〕
A: No odor is felt.
○: Almost no odor is felt.
Δ: Some odor is felt, but there is no practical problem.
X: Odor is felt strongly.

  Based on the above results, the toners of the examples were compared with the toners of Comparative Example 1 in which a resin using unmodified rosin was used in combination and Comparative Example 2 which contained a resin not using modified rosin alone. It can be seen that not only the low-temperature fixing property and the offset resistance are excellent, the durability and the filming resistance are also good, but also the storage stability is good even in a severe environment.

  The toner for electrophotography of the present invention is used for developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method and the like.

Claims (9)

  A toner comprising a polyester resin (A) and a polyester resin (B) having a softening point higher than that of the polyester resin (A) by 10 ° C. or more as a binder resin, the polyester resin (A) And at least one of (B) is a resin derived from (meth) acrylic acid-modified rosin having a polyester unit obtained by condensation polymerization of an alcohol component and a carboxylic acid component containing (meth) acrylic acid-modified rosin. An electrophotographic toner.   2. The electrophotographic toner according to claim 1, wherein the content of the (meth) acrylic acid-modified rosin in the carboxylic acid component of the resin derived from the (meth) acrylic acid-modified rosin is 5 to 85% by weight.   The toner for electrophotography according to claim 1 or 2, wherein the (meth) acrylic acid-modified rosin is obtained by modifying a purified rosin with (meth) acrylic acid.   The alcohol component of the resin derived from (meth) acrylic acid-modified rosin contains a trihydric or higher polyhydric alcohol and / or the carboxylic acid component contains a trivalent or higher polyvalent carboxylic acid compound. Or a toner for electrophotography.   The toner for electrophotography according to claim 1, wherein at least the polyester resin (A) is a resin derived from (meth) acrylic acid-modified rosin.   The electrophotographic toner according to claim 1, wherein the content of the resin derived from (meth) acrylic acid-modified rosin in the binder resin is 70% by weight or more.   The toner for electrophotography according to any one of claims 1 to 6, wherein the degree of (meth) acrylic acid modification of the (meth) acrylic acid-modified rosin is 5 to 105.   The toner for electrophotography according to any one of claims 1 to 7, wherein the softening point of the polyester resin (A) is 80 to 120 ° C, and the softening point of the polyester resin (B) is 100 to 180 ° C.   A method for producing a toner comprising at least a step of melt-kneading a polyester resin (A) and a polyester resin (B) having a softening point higher by 10 ° C. or more than that of the polyester resin (A), the polyester resin ( At least one of A) and (B) is derived from a (meth) acrylic acid-modified rosin having a polyester unit obtained by condensation polymerization of an alcohol component and a carboxylic acid component containing a (meth) acrylic acid-modified rosin. A method for producing an electrophotographic toner which is a resin.